1. Field of the Invention
The invention relates in general to a backlight module and a liquid crystal display (LCD) formed therefrom, and more particularly to a backlight module having a heat dissipation channel formed between a diffuser and a top plate of a bezel.
2. Description of the Related Art
Because of the rapid advance of the technology of manufacturing the liquid crystal display (LCD) and the LCD has the advantages of light, thin, power-saving and radiationless properties, the LCDs are widely used in various electrical products, such as personal digital assistants (PDAs), notebook computers, digital cameras, digital camcorders, mobile telephones, computer monitors and liquid crystal televisions. However, because the LCD panel in the LCD is a display panel that cannot emit light itself, a backlight module is needed to provide light so that the display function can be achieved. The conventional backlight module includes a bezel, a reflector, several cold cathode fluorescent lamps (CCFLs), a diffuser and an optical film set. The bezel includes a bottom plate, a top plate and an inclined lateral plate for connecting the bottom plate to the top plate. The bottom plate, the top plate and the inclined lateral plate define a downward concave space. The reflector is positioned above the downward concave space and attached on the bottom plate of the bezel and one part of the inclined lateral plate. The CCFL for providing light is positioned in the downward concave space and disposed above the reflector. The diffuser is disposed on the bezel and positioned above the CCFL. The optical film set is disposed above the diffuser. In addition, the edge of the diffuser usually contacts one part of the top plate to seal the opening of the downward concave space.
However, the CCFL generates heat to cause high temperature while emitting light. Because the edge of the diffuser contacts one part of the top plate to seal the opening of the downward concave space, the heat generated by the CCFL in the downward concave space cannot be dissipated to the outside. More particularly, as the required brightness of the LCD is gradually increasing, the increased brightness of the CCFL inevitably generates more heat, and the internal environmental temperature of the LCD is thus increased. Consequently, the working environmental temperature of the CCFL is increased a lot, thereby deteriorating the light emitting quality of the CCFL and thus greatly influencing the operating quality of the backlight module. Similarly, the backlight module using light emitting diodes (LEDs) to provide light also encounters the above-mentioned problems.